C-4 (Tamiami) Canal Flood Relief Project

The Tamiami Canal extends from the Everglades to the Miami River.

In response to major flooding in South Florida during October 2000, much-needed relief was sought in the form of a regional reservoir. It was thought that the Tamiami Canal could, during heavy storm events, be used to accept stormwater from municipal systems, at the same time discharging that stormwater to the proposed impoundment through pumps. PBS&J was charged with developing and calibrating an H&H model that could assess the capacity of the canal to function in this manner.

PBS&J’s application of the XPSWMM H&H model for hydrodynamic simulation of flows proved to be the best choice for meeting the project’s requirements of a model with robust routines for handling structures such as weirs and pumps in series that could be activated via gauges at remote locations, as well as a linkage to groundwater data to account for the seepage emanating from the Everglades. Seepage from the Everglades created a critical base flow condition that affected the flood conveyance capacity of the model. Accordingly, PBS&J used an innovative technique to account for the seepage that was taking place across the Everglades dike into the C-4 basin area. Using an updated and modified version of the SFWMD MODFLOW regional model for the Miami-Dade County area together with PBS&J’s generated H&H model, PBS&J was able to successfully achieve accurate calibration of both dry weather base flows and flows for historical storm event conditions.

Flood mitigation projects for the impacted areas include a regional detention facility,  forward and backpumping facilities, canal dredging and berm construction.